Nursing care
Autonomic dysreflexia vs neurogenic shock: one pressure goes up, the other goes down
Written and reviewed by Kevin Patel, MSN, RN, CCRN · 3 min read · Updated November 2026
Short answer
Blood pressure separates them. Autonomic dysreflexia causes a sudden, dangerous rise in blood pressure, usually months after a spinal cord injury at T6 or above, triggered by something like a full bladder. Neurogenic shock causes low blood pressure in the first hours to days after the injury. Both can show a slow heart rate, so the pulse does not tell them apart.
Which way the pressure moves
In autonomic dysreflexia, a stimulus below the injury, most often an overfull bladder, sets off a reflex surge in sympathetic tone. Vessels below the lesion clamp down and blood pressure climbs. The brain senses the rise and tries to calm it, but the signal cannot pass the injured cord, so the pressure keeps rising.
Neurogenic shock is the opposite problem. OpenStax describes it as a distributive shock: the injury cuts sympathetic control of the vessels, they dilate, and blood pressure falls without any blood being lost. Systolic readings under 90 are typical, and fluids alone often fail to bring the pressure up.
Why both can have a slow pulse
Students often expect a fast pulse with any shock, then miss neurogenic shock. Here the vagus nerve still works while sympathetic input is gone, so the heart slows. OpenStax lists bradycardia under 60 alongside hypotension as the hallmark pair.
Autonomic dysreflexia can also slow the heart; UMass Memorial Health lists a slow heart rate among its signs as the body reacts to the pressure spike. So a heart rate of 52 does not identify either condition. The blood pressure reading, the skin and the time since injury do.
Timing after injury and what the skin shows
Neurogenic shock is an early problem, seen in the acute period after a cervical or high thoracic injury. OpenStax notes it most often follows injuries above T7, with warm skin at first and trouble holding body temperature.
Autonomic dysreflexia comes later. UMass Memorial Health states it is unusual within the first month after injury but often appears within the first year, in people with injuries at T6 or higher. The client describes a severe, pounding headache, with flushing and sweating above the injury and pale, cool skin below it.
First actions for each emergency
What is the first action for autonomic dysreflexia? Sit the client up with the head raised, which lowers pressure, then loosen tight clothing and look for the trigger: check the catheter for kinks, empty the bladder, then check for stool and skin irritation. Recheck blood pressure often and escalate quickly if it stays high after the likely cause is removed.
For neurogenic shock, the order is reversed. Keep the client flat with spinal precautions, support airway and breathing, give fluids and vasopressors as ordered, and expect atropine for symptomatic bradycardia. Raising the head of a hypotensive client would make the pressure worse, which is why the sitting-up reflex from dysreflexia does not transfer.
Hypothetical practice scenario
Hypothetical scenario, not a real exam item: a client with a C6 injury from eight months ago reports a pounding headache. Blood pressure is 190/104, pulse 54, and the face is flushed. Which action comes first: call the provider, sit the client up, or give a pain reliever for the headache?
Sit the client up. Calling the provider is reasonable later, but it delays a step that lowers pressure right away. Treating the headache as a pain problem misses that the headache is a symptom of the pressure. After positioning, the next step is looking for the trigger, starting with the bladder.
Sources and further reading
OpenStax Medical-Surgical Nursing: 23.4 Neurogenic Shock. Distributive mechanism, hypotension and bradycardia, injuries above T7, warm skin and thermoregulation, fluids, vasopressors and atropine, nursing priorities.
UMass Memorial Health: Autonomic Dysreflexia. T6 or higher, timing after injury, symptoms above and below the injury, triggers, sitting up, loosening clothing, checking bladder and bowel.
The next step on this is the same as on everything else here: answer questions and read the rationales. Our neurological practice questions are the closest set to what this page covers.
Common questions
Is blood pressure high or low in autonomic dysreflexia?
High, often dangerously so. The rise comes from a reflex surge below the injury that the brain cannot switch off. In neurogenic shock the pressure is low because the vessels have lost sympathetic tone.
When does autonomic dysreflexia occur after SCI?
It is unusual in the first month after injury and often appears within the first year, in people with injuries at T6 or higher. It can recur for life whenever a trigger such as a full bladder or constipation occurs.
What are common triggers of autonomic dysreflexia?
Bladder problems lead the list: an overfull bladder, a blocked catheter or a urinary tract infection. Constipation, pressure injuries, tight clothing, ingrown nails and sunburn can also trigger an episode.